An automatic assembly line for lens modules may use, for example, a robotic arm to pick up (e.g., by suction, claw or otherwise) lens elements from a lens holder such as a lens tray, and to assemble them into a lens barrel. It is important and often critical to know a precise location and orientation of each lens element, so that the robotic arm can pick up the lens elements from the lens tray. If a lens element shifts and changes its position on the lens tray, and if the lens element is picked up by suction, the amount of suction may not be enough to successfully pick up the lens element.
FIG. 5 illustrates a conventional apparatus for assembling lenses. The apparatus 100 includes a lens tray 10, a support 12 and two positioning pins 14. The lens tray 10 defines a plurality of lens-receiving holes 102 for receiving lens elements and two positioning holes 104. The lens-receiving holes 102 are arranged in a matrix array on one surface of the lens tray 10 and the two positioning holes 104 are defined at two across corners of the lens tray 10. The positioning pins 14 are fixed on the support 12 and correspond to the two positioning holes 104 separately. In use, the two positioning pins 14 extend through the positioning holes 104 and thus the lens tray 10 is located on the support 12.
However, the lens tray 10 may be shaken by accidental contact with a foreign object. The shaking of the lens tray 10 may cause the lens elements received in the lens-receiving holes 102 to change their position. In order to assemble them accurately, the positions must be readjusted, thus wasting time, thereby reducing efficiency.
What is needed, therefore, is to provide an apparatus for assembling lenses that can prevent the lens tray from shaking.